Some but not all of the publishers, according to the report, have moved to settlement discussions with the government before any such lawsuit is filed, hoping to avoid a public and very messy fight. Whether the parties settle or go to court, at stake is the agency pricing model Apple helped introduce to the e-book industry, where publishers set fixed prices across all e-bookstores and retailers recoup a set percentage of the sales.

The DOJ is reportedly concerned that agency pricing — and its uniform adoption by five of the big six publishers, timed with the launch and rollout of Apple's iBooks — has reduced competition in the industry, with the overall effect of raising e-book prices for consumers. A federal class-action lawsuit filed in August against Apple and the same group of publishers (HarperCollins, Hachette Book Group, Macmillan, Penguin Group Inc., and Simon & Schuster Inc.) raised similar concerns, pointing to higher e-book prices as a result of the defendants' actions. A settlement or lawsuit could either restructure agency pricing or eliminate it altogether.

In an interview with biographer Walter Isaacson, Steve Jobs explained how Apple and the publishers implemented the agency model, and how the publishers expanded it to Amazon:

We told the publishers, "We'll go to the agency model, where you set the price, and we get our 30%, and yes, the customer pays a little more, but that's what you want anyway…" They went to Amazon and said, "You're going to sign an agency contract or we're not going to give you the books."

It's a fine point, but what any lawsuit would turn on whether the five publishers worked together to coordinate their negotiations with both Apple and Amazon. That's the standard for collusion; that's what raises genuine antitrust concerns.

Prior to Apple's entry to the market — and in many cases still — e-books were generally sold wholesale: publishers and retailers negotiated a fixed cost per unit, and retailers are then free to charge customers whatever they like. But wholesale pricing causes two problems for publishers: it gives market leaders (read: Amazon) disproportionate negotiating power, and makes it possible to use heavily discounted e-books to boost sales figures, capture market share and sharply undercut sales of printed books.

Wholesale pricing is no wholesale fix. Nor is it by any means certain that this would be the outcome. Agency pricing can be technically altered to meet whatever legitimate antitrust issues the DOJ may raise. And the legal case against the publishers for collusion is by no means clear, in part because publishers have been to this dance before.

"This is an industry that has been beat up 9 ways from Sunday with the Robinson Patman Act," publishing consultant Joseph Esposito wrote in an email. (The Robinson-Patman Act is a little different, because it's about setting different prices for different groups of purchasers, but touches on the same collusion issues.) "Everybody who works on the business side has been trained to avoid the appearance of collusion," Esposito added. "These very sophisticated companies have already worked through a scenario in which they are sued and have a defense planned."

A strategic settlement seems more likely. "A settlement is being considered for pragmatic reasons but by no means are we close," a publishing executive told the WSJ. "You have to consider a settlement, whether you think it's fair or not."